Problems, Solutions, and Strategies Reported by Users of Transcutaneous Electrical Nerve Stimulation for Chronic Musculoskeletal Pain: Qualitative Exploration Using Patient Interviews

Low back pain patients' perceived effectiveness of utilizing complementary and alternative medicine: a systematic review of qualitative studies

OBJECTIVES

The purpose of this systematic review of qualitative studies is to explore patients' perceived effectiveness of utilizing complementary and alternative medicine (CAM) for the treatment and/or management of low back pain (LBP).

METHODS

MEDLINE, EMBASE, AMED, and CINAHL were systematically searched from database inception until May 2020. Eligible articles included qualitative data about LBP patients' perceptions of using CAM.

RESULTS

Of 1,567 items, 1,542 items were excluded; the remaining 25 articles were included in this review. Three themes emerged as follows: physical benefits; mental health benefits; and negative or no perceived effectiveness of CAM on patients with LBP.

CONCLUSIONS

This study explores perceptions of CAM effectiveness among patients with LBP. These findings provide valuable information to CAM and non-CAM practitioners regarding the importance of individualized patient care based on their preferences, values, needs, and perspectives. Further exploration could include practitioners' perceptions of CAM and their impact on the patient-practitioner relationship.

Characterising the Features of 381 Clinical Studies Evaluating Transcutaneous Electrical Nerve Stimulation (TENS) for Pain Relief: A Secondary Analysis of the Meta-TENS Study to Improve Future Research

Background and Objectives: Characterising the features of methodologies, clinical attributes and intervention protocols, of studies is valuable to advise directions for research and practice. This article reports the findings of a secondary analysis of the features from studies screened as part of a large systematic review of TENS (the meta-TENS study). Materials and Methods: A descriptive analysis was performed on information associated with methodology, sample populations and intervention protocols from 381 randomised controlled trials (24,532 participants) evaluating TENS delivered at a strong comfortable intensity at the painful site in adults with pain, irrespective of diagnosis. Results: Studies were conducted in 43 countries commonly using parallel group design (n = 334) and one comparator group (n = 231). Mean ± standard deviation (SD) study sample size (64.05 ± 58.29 participants) and TENS group size (27.67 ± 21.90 participants) were small, with only 13 of 381 studies having 100 participants or more in the TENS group. Most TENS interventions were ‘high frequency’ (>10 pps, n = 276) and using 100 Hz (109/353 reports that stated a pulse frequency value). Of 476 comparator groups, 54.2% were active treatments (i.e., analgesic medication(s), exercise, manual therapies and electrophysical agents). Of 202 placebo comparator groups, 155 used a TENS device that did not deliver currents. At least 216 of 383 study groups were able to access other treatments whilst receiving TENS. Only 136 out of 381 reports included a statement about adverse events. Conclusions: Clinical studies on TENS are dominated by small parallel group evaluations of high frequency TENS that are often contaminated by concurrent treatment(s). Study reports tended focus on physiological and clinical implications rather than the veracity of methodology and findings. Previously published criteria for designing and reporting TENS studies were neglected and this should be corrected in future research using insights gleaned from this analysis.

An assessment of sensory sensitivity in women suffering from depression using transcutaneous electrical nerve stimulation

Background

Perception is the process or result of the process arising from the mental interpretation of the phenomena occurring, therefore it depends not only on physiology, but is also psychologically and socially conditioned. The aim of this study was to assess if there is a difference in the sensory sensitivity to an electrical stimulus in women suffering from depression and what the hedonic rating is of the lived experience of transcutaneous electrical nerve stimulation.

Methods

The depression group: 44 women, who were inpatients treated for depression at the Psychiatric Ward in the Clinical Hospital, and the control group: 41 women, matched by the age, height and weight, with no mental illness. Measures: threshold for sensing current, type of sensation evoked, hedonic rating.

Results

Median sensing threshold of electric current (depression vs. control: 7.75 mA vs. 8.35 mA; no significant), type of sensation evoked (depression vs. control: tingling 90.9% vs. 92.7%, no significant), hedonic rating (depression vs. control: unpleasant 11.4% vs. 2.4%; p = 0.003), hedonic rating (mildly ill vs. moderately ill vs. markedly ill: unpleasant 5.3% vs. 6.3% vs. 33.3%; p = 0.066).

Conclusions

Women suffering from depression exhibit a similar threshold of sensitivity to an electrical stimulus as mentally healthy women, however the hedonic rating of the stimulus acting on the skin in the group of clinically depressed women was more negative than in the mentally healthy subjects. The stimulus was described as 'unpleasant' for many of the mentally unhealthy women. The most negative sensations related to the electrical stimulus were experienced by women with the highest severity of mental illness according to The Clinical Global Impression - Severity Scale.

Foundational Research Could Improve Future Transcutaneous Electrical Nerve Stimulation Evaluations

Background and objectives: There is a lack of good quality evidence regarding the effectiveness of transcutaneous electrical nerve stimulation (TENS) for chronic musculoskeletal pain, including chronic low back pain. High quality randomised controlled trials (RCTs) have been called for to establish effectiveness over and above placebo and some guidance has already been offered regarding the design of such trials. This article expands the discussion regarding the design of future TENS trials. There is qualitative evidence of the complexity of TENS as an intervention which should be considered in future TENS evaluations. This complexity includes multiple benefits reported by patients, depending on their chosen contexts of TENS use. The ideal content and delivery of support for patients to optimise TENS use also lacks consensus. There is no evidence that a TENS education package has been designed to support the complex set of behaviours and choices which experienced users suggest are required to optimise TENS benefits. Finally, clinical and research outcomes have not been contextualised and related to the specific strategies of use. Conclusions: We suggest that research is required to develop consensus about the content and delivery of training in TENS use for patients who live with pain, informed by the experience of patients, clinicians, and researchers. Once a consensus about the content of TENS training has been reached, there is then a need to develop a TENS training course (TTC) based on this content. An effective and acceptable TTC is needed to develop the knowledge and skills required to optimise TENS use, supporting patients to build confidence in using TENS in everyday life situations with the aim of reducing the impact of chronic pain on function and quality of life. Further research is required to extend the evidence base regarding appropriate, contextualised TENS patient-reported outcomes.

Does TENS Reduce the Intensity of Acute and Chronic Pain? A Comprehensive Appraisal of the Characteristics and Outcomes of 169 Reviews and 49 Meta-Analyses

Background and Objectives: Uncertainty about the clinical efficacy of transcutaneous electric nerve stimulation (TENS) to alleviate pain spans half a century. There has been no attempt to synthesise the entire body of systematic review evidence. The aim of this comprehensive review was to critically appraise the characteristics and outcomes of systematic reviews evaluating the clinical efficacy of TENS for any type of acute and chronic pain in adults. Materials and Methods: We searched electronic databases for full reports of systematic reviews of studies, overviews of systematic reviews, and hybrid reviews that evaluated the efficacy of TENS for any type of clinical pain in adults. We screened reports against eligibility criteria and extracted data related to the characteristics and outcomes of the review, including effect size estimates. We conducted a descriptive analysis of extracted data. Results: We included 169 reviews consisting of eight overviews, seven hybrid reviews and 154 systematic reviews with 49 meta-analyses. A tally of authors' conclusions found a tendency toward benefits from TENS in 69/169 reviews, no benefits in 13/169 reviews, and inconclusive evidence in 87/169 reviews. Only three meta-analyses pooled sufficient data to have confidence in the effect size estimate (i.e., pooled analysis of >500 events). Lower pain intensity was found during TENS compared with control for chronic musculoskeletal pain and labour pain, and lower analgesic consumption was found post-surgery during TENS. The appraisal revealed repeated shortcomings in RCTs that have hindered confident judgements about efficacy, resulting in stagnation of evidence. Conclusions: Our appraisal reveals examples of meta-analyses with 'sufficient data' demonstrating benefit. There were no examples of meta-analyses with 'sufficient data' demonstrating no benefit. Therefore, we recommend that TENS should be considered as a treatment option. The considerable quantity of reviews with 'insufficient data' and meaningless findings have clouded the issue of efficacy. We offer solutions to these issues going forward.

Noninvasive neuromodulation reduces symptoms of restless legs syndrome

STUDY OBJECTIVES

Restless legs syndrome (RLS) is a common neurological disorder characterized by an uncontrollable nocturnal urge to move the legs and often associated with chronic sleep disturbances. The most common treatments for RLS are medications that can have debilitating side-effects. Here, we evaluated a novel alternative modality of RLS treatment, noninvasive bilateral electrical stimulation of the common peroneal nerve.

METHODS

To assess the impact of this noninvasive peripheral nerve stimulation (NPNS) approach on RLS symptomatology, we conducted a multi-site randomized crossover study comparing NPNS to sham. RLS patients with moderate to severe RLS (n=37) self-administered NPNS and sham nightly for 14 days per treatment in randomized order.

RESULTS

NPNS resulted in a reduction in RLS severity of 6.81 points on the International RLS Rating Scale (IRLS) relative to 3.38 for sham (p<0.01) and a 66% clinically significant responder rate on the Clinical Global Impressions-Improvement (CGI-I) scale compared to 17% for sham (p<0.01). Subgroup analysis indicated that medication-resistant and medication-naïve participants both exhibited similarly robust responses. There were no moderate or serious device-related adverse events.

CONCLUSIONS

These results suggest that NPNS could be a promising alternative to pharmacological therapies for RLS and could provide a solution for medication-resistant RLS patients and for medication-naïve RLS patients who are unwilling or unable to take medication.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Noninvasive Peripheral Nerve Stimulation for Restless Legs Syndrome; Identifier: NCT04700683; URL: https://clinicaltrials.gov/ct2/show/NCT04700683.

Resolving Long-Standing Uncertainty about the Clinical Efficacy of Transcutaneous Electrical Nerve Stimulation (TENS) to Relieve Pain: A Comprehensive Review of Factors Influencing Outcome

Pain is managed using a biopsychosocial approach and pharmacological and non-pharmacological treatments. Transcutaneous electrical nerve stimulation (TENS) is a technique whereby pulsed electrical currents are administered through the intact surface of the skin with the intention of alleviating pain, akin to 'electrically rubbing pain away'. Despite over 50 years of published research, uncertainty about the clinical efficacy of TENS remains. The purpose of this comprehensive review is to critically appraise clinical research on TENS to inform future strategies to resolve the 'efficacy-impasse'. The principles and practices of TENS are described to provide context for readers unfamiliar with TENS treatment. The findings of systematic reviews evaluating TENS are described from a historical perspective to provide context for a critical evaluation of factors influencing the outcomes of randomized controlled trials (RCTs); including sample populations, outcome measures, TENS techniques, and comparator interventions. Three possibilities are offered to resolve the impasse. Firstly, to conduct large multi-centered RCTs using an enriched enrolment with randomized withdrawal design, that incorporates a 'run-in phase' to screen for potential TENS responders and to optimise TENS treatment according to individual need. Secondly, to meta-analyze published RCT data, irrespective of type of pain, to determine whether TENS reduces the intensity of pain during stimulation, and to include a detailed assessment of levels of certainty and precision. Thirdly, to concede that it may be impossible to determine efficacy due to insurmountable methodological, logistical and financial challenges. The consequences to clinicians, policy makers and funders of this third scenario are discussed. I argue that patients will continue to use TENS irrespective of the views of clinicians, policy makers, funders or guideline panel recommendations, because TENS is readily available without prescription; TENS generates a pleasant sensory experience that is similar to easing pain using warming and cooling techniques; and technological developments such as smart wearable TENS devices will improve usability in the future. Thus, research is needed on how best to integrate TENS into existing pain management strategies by analyzing data of TENS usage by expert-patients in real-world settings.

Study protocol randomised controlled trial comparison of cost-utility and cost-effectiveness of a face-to-face rehabilitation programme versus a telemedicine programme in the treatment of patients with chronic low back pain

INTRODUCTION

Chronic lower back pain is a highly prevalent medical condition in Western countries, which that incurs a considerable social and economic burden. Although prescription exercise at home for chronic pain has become a widely used alternative to reduce healthcare costs, the evidence regarding patient adherence and decreased in costs in European countries is scarce and inconclusive. The objective of this study is to examine the cost-utility and cost-effectiveness in patients with chronic lower back pain treated with the McKenzie Method and electroanalgesia via a telemedicine programme versus a face-to-face programme.

METHODS AND ANALYSIS

This study reports the protocol for a randomised, two-arm, multicentre, parallel controlled trial. A total of 540 patients with chronic lower back pain (onset time ≥3 months, Roland Morris Disability Questionnaire ≥4) will be recruited in three hospitals in Andalusia. Participants will be assigned to one of two groups (n=270, respectively) to receive electroanalgesia and Mckenzie method exercises through a telemedicine or a face-to-face programme. A total of 24 sessions will be administered three times a week for 8 weeks. Since the study design does not allow participant blinding, the outcome assessor and the statistician will be blinded. Use of helth care resources and costs due to work absenteeism will be captured and analysed. In addition, pain, intensity, fear of movement, quality of life and strength of the core muscle and anteflexion lumbar will be recorded at 2 and 6 months after the start of treatment.

ETHICS AND DISSEMINATION

Human Research and Local Ethics Committee of the 'Hospital Complex Torrecárdenas of Almeria, University Hospital of Granada and Virgen Macarena de Sevilla Hospital-Andalusian Health Service'. Study findings will be released to the research, clinical and health service through publication in international journals and conferences.

TRIAL REGISTRATION NUMBER

NCT04266366.

Matching the perceived benefits of Transcutaneous Electrical Nerve Stimulation (TENS) for chronic musculoskeletal pain against Patient Reported Outcome Measures using the International Classification of Functioning, Disability and Health (ICF)

BACKGROUND

There is no consensus regarding the effectiveness of Transcutaneous Electrical Nerve Stimulation (TENS) for chronic musculoskeletal or low back pain. A review of previous trial methodology identified problems with treatment fidelity. Qualitative research with experienced TENS users identified specific contexts for TENS use, leading to individualised outcomes. There is little information available to guide the selection of Patient Reported Outcome Measures (PROMs) appropriate for TENS evaluation.

OBJECTIVE

To determine the capability of previously used PROMs to capture the perceived benefits of TENS reported by secondary care Pain Clinic patients who successfully used TENS to manage chronic musculoskeletal pain.

DESIGN

The World Health Organisation International Classification of Functioning, Disability and Health (ICF) was used to match the perceived benefits of TENS against previously used PROMS.

METHODS

Semi-structured interviews conducted with nine patients (6 women) as well as three other qualitative datasets (88 patients in total) generated patient-reported benefits which were matched against previously used PROMs using the ICF.

FINDINGS

There were 18 items in the final list of benefits, and none of the four functional outcome measures used in previous RCTs captured more than 8 of these 18 items. The data analysis complemented the inductive thematic analysis but could not replace it, indicating the value of both forms of analysis.

CONCLUSIONS

This study highlights a low level of match between outcome measures used in previous TENS studies, and the benefits perceived by experienced TENS users. This suggests that further work is required if the patient-reported benefits of TENS are to be evaluated.

Randomized study of the impact of a therapeutic education program on patients suffering from chronic low-back pain who are treated with transcutaneous electrical nerve stimulation

BACKGROUND

Transcutaneous electrical nerve stimulation (TENS) is often used for the treatment of low-back pain (LBP). However, its effectiveness is controversial.

OBJECTIVE

To determine the efficacy of TENS in the treatment LBP when associated to a therapeutic education program (TEP).

DESIGN

Open randomized monocentric study.

SETTING

University hospital between 2010 and 2014.

PATIENTS

A total of 97 patients suffering from LBP.

INTERVENTIONS

Routine care (TENS group) or routine care plus a therapeutic education program (TENS-TEP group) based on consultation support by a pain resource nurse.

MAIN OUTCOME MEASURES

EIFEL and Dallas Pain Questionnaire scores.

RESULTS

Twenty-two patients (44%) were still assessable at the end-of-study visit, whereas 33 (70%) were assessable at the same time point in the TENS-TEP group (P = .013). The EIFEL score and the Dallas score had a similar evolution over time between groups (P = .18 and P = .50 respectively). Similarly, there were no significant differences between the groups with respect to resting pain scores (P = .94 for back pain and P = .16 for leg pain) and movement pain scores (P = .52 for back pain and P = .56 for leg pain). At Month 6, there was no significant difference between the groups (P = .85) with regard to analgesics and social impact. Two patients presented a serious adverse event during the study (one in each group) but non-attributable to the treatment studied.

CONCLUSION

This study does not support the use of TENS in the treatment of patients with chronic LBP even though patients benefited from a therapeutic education program by a pain resource nurse. However, the higher number of premature withdrawals in the TENS group may be due to early withdrawal of patients who did not experience improvement of their symptoms.

Non-invasive peripheral nerve stimulation via focused ultrasound in vivo

Focused ultrasound (FUS) has been employed on a wide range of clinical applications to safely and non-invasively achieve desired effects that have previously required invasive and lengthy procedures with conventional methods. Conventional electrical neuromodulation therapies that are applied to the peripheral nervous system (PNS) are invasive and/or non-specific. Recently, focused ultrasound has demonstrated the ability to modulate the central nervous system and ex vivo peripheral neurons. Here, for the first time, noninvasive stimulation of the sciatic nerve eliciting a physiological response in vivo is demonstrated with FUS. FUS was applied on the sciatic nerve in mice with simultaneous electromyography (EMG) on the tibialis anterior muscle. EMG signals were detected during or directly after ultrasound stimulation along with observable muscle contraction of the hind limb. Transecting the sciatic nerve downstream of FUS stimulation eliminated EMG activity during FUS stimulation. Peak-to-peak EMG response amplitudes and latency were found to be comparable to conventional electrical stimulation methods. Histology along with behavioral and thermal testing did not indicate damage to the nerve or surrounding regions. The findings presented herein demonstrate that FUS can serve as a targeted, safe and non-invasive alternative to conventional peripheral nervous system stimulation to treat peripheral neuropathic diseases in the clinic.

Transcutaneous electrical nerve stimulation (TENS) for fibromyalgia in adults

BACKGROUND

Fibromyalgia is characterised by persistent, widespread pain; sleep problems; and fatigue. Transcutaneous electrical nerve stimulation (TENS) is the delivery of pulsed electrical currents across the intact surface of the skin to stimulate peripheral nerves and is used extensively to manage painful conditions. TENS is inexpensive, safe, and can be self-administered. TENS reduces pain during movement in some people so it may be a useful adjunct to assist participation in exercise and activities of daily living. To date, there has been only one systematic review in 2012 which included TENS, amongst other treatments, for fibromyalgia, and the authors concluded that TENS was not effective.

OBJECTIVES

To assess the analgesic efficacy and adverse events of TENS alone or added to usual care (including exercise) compared with placebo (sham) TENS; no treatment; exercise alone; or other treatment including medication, electroacupuncture, warmth therapy, or hydrotherapy for fibromyalgia in adults.

SEARCH METHODS

We searched the following electronic databases up to 18 January 2017: CENTRAL (CRSO); MEDLINE (Ovid); Embase (Ovid); CINAHL (EBSCO); PsycINFO (Ovid); LILACS; PEDRO; Web of Science (ISI); AMED (Ovid); and SPORTDiscus (EBSCO). We also searched three trial registries. There were no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-randomised trials of TENS treatment for pain associated with fibromyalgia in adults. We included cross-over and parallel-group trial designs. We included studies that evaluated TENS administered using non-invasive techniques at intensities that produced perceptible TENS sensations during stimulation at either the site of pain or over nerve bundles proximal (or near) to the site of pain. We included TENS administered as a sole treatment or TENS in combination with other treatments, and TENS given as a single treatment or as a course of treatments.

DATA COLLECTION AND ANALYSIS

Two review authors independently determined study eligibility by assessing each record and reaching agreement by discussion. A third review author acted as arbiter. We did not anonymise the records of studies before assessment. Two review authors independently extracted data and assessed risk of bias of included studies before entering information into a 'Characteristics of included studies' table. Primary outcomes were participant-reported pain relief from baseline of 30% or greater or 50% or greater, and Patient Global Impression of Change (PGIC). We assessed the evidence using GRADE and added 'Summary of findings' tables.

MAIN RESULTS

We included eight studies (seven RCTs, one quasi-RCT, 315 adults (299 women), aged 18 to 75 years): six used a parallel-group design and two used a cross-over design. Sample sizes of intervention arms were five to 43 participants.Two studies, one of which was a cross-over design, compared TENS with placebo TENS (82 participants), one study compared TENS with no treatment (43 participants), and four studies compared TENS with other treatments (medication (two studies, 74 participants), electroacupuncture (one study, 44 participants), superficial warmth (one cross-over study, 32 participants), and hydrotherapy (one study, 10 participants)). Two studies compared TENS plus exercise with exercise alone (98 participants, 49 per treatment arm). None of the studies measured participant-reported pain relief of 50% or greater or PGIC. Overall, the studies were at unclear or high risk of bias, and in particular all were at high risk of bias for sample size.Only one study (14 participants) measured the primary outcome participant-reported pain relief of 30% or greater. Thirty percent achieved 30% or greater reduction in pain with TENS and exercise compared with 13% with exercise alone. One study found 10/28 participants reported pain relief of 25% or greater with TENS compared with 10/24 participants using superficial warmth (42 °C). We judged that statistical pooling was not possible because there were insufficient data and outcomes were not homogeneous.There were no data for the primary outcomes participant-reported pain relief from baseline of 50% or greater and PGIC.There was a paucity of data for secondary outcomes. One pilot cross-over study of 43 participants found that the mean (95% confidence intervals (CI)) decrease in pain intensity on movement (100-mm visual analogue scale (VAS)) during one 30-minute treatment was 11.1 mm (95% CI 5.9 to 16.3) for TENS and 2.3 mm (95% CI 2.4 to 7.7) for placebo TENS. There were no significant differences between TENS and placebo for pain at rest. One parallel group study of 39 participants found that mean ± standard deviation (SD) pain intensity (100-mm VAS) decreased from 85 ± 20 mm at baseline to 43 ± 20 mm after one week of dual-site TENS; decreased from 85 ± 10 mm at baseline to 60 ± 10 mm after single-site TENS; and decreased from 82 ± 20 mm at baseline to 80 ± 20 mm after one week of placebo TENS. The authors of seven studies concluded that TENS relieved pain but the findings of single small studies are unlikely to be correct.One study found clinically important improvements in Fibromyalgia Impact Questionnaire (FIQ) subscales for work performance, fatigue, stiffness, anxiety, and depression for TENS with exercise compared with exercise alone. One study found no additional improvements in FIQ scores when TENS was added to the first three weeks of a 12-week supervised exercise programme.No serious adverse events were reported in any of the studies although there were reports of TENS causing minor discomfort in a total of 3 participants.The quality of evidence was very low. We downgraded the GRADE rating mostly due to a lack of data; therefore, we have little confidence in the effect estimates where available.

AUTHORS' CONCLUSIONS

There was insufficient high-quality evidence to support or refute the use of TENS for fibromyalgia. We found a small number of inadequately powered studies with incomplete reporting of methodologies and treatment interventions.